Note: Descriptions are shown in the official language in which they were submitted.
1~45779
- BRATORY SAND RECLAIMIN~, APPARATUS
.
BACK~ROUND OF THE INVENTION
In most foundry operations, hot metal is poured into a
mold cavity produced by a pattern. The mold cavity is sometimes
produced by compressing sand and clay binders toge-ther with water
to produce a formable mixture which will retain the shape of
the pattern. In other processes, the pattern is surrounded by
sand which has been treated with a resin binder, which binder
hardens in air within a relatively short period of time.
Occasionally metal cores and metal ro~s are used to reinforce
the mold, such rods and cores being embedded in -the sand at
appropriate places.
Because of the increased costs of the sand and other
materials used in forming a mold, and because of the cost of
disposing of such materials if the~ are considered scrap, the
foundry industry has been faced with the problem of reclaiming
sand for reuse in molding operations. The practice heretofore
has been simply to place the sand, after the casting has been
removed, onto a vibratory screen or other screening apparatus
provided with horizontal decks, through which the sand particles
pass for reuse. In such processes, only a portion of the sand
is recovered for reuse and a good deal still results as waste
or scrap material.
BRIEF SUMMARY OF THE INVENTION
After the casting operation has been completed and the
casting withdrawn from the mold, the latter compxesses lumps of r
sand cemented together with binders or other cementious material
as well as embedded rods, cores, and the like. If two of the
lumps are rubbed together, they are mutually abrasive and discrete
particles of sand will be removed from each of the lumps. If such !~
rubbing is continued, the lump is substantially entirely reduced
to particulate form and all embedded rods, cores, and the like
are released from the sand.
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~45779
he present invention provides a chamber mounted for
bratory movement and provided with a floor which slants up-
wardly toward an exlt. Lumps of sand directly from the mold are
introduced into the chamber and the latter is vibrated causing
the lumps to rub together, thereby producing particulate sand
as well as freeing any included material. A sand bed is built
up in the bottom of the chamber and as its volume increases,
such increased volume together with the vibratory movement
moves the particulate sand upwardly toward a discharge opening
through which the partic~late sand may pass for reuse.
Thus, the invention contemplates an apparatus for re-
claiming foundry sand from lumps of previously used foundry sand
which comprises means forming a closed chamber, a floor in the
chamber having a portion slanting upwardly from the horizontal,
an exit from the chamber at the upper end of the slanting portion
of the floor, an entrance to the chamber to permit the introd-
uction of lumps of sand thereinto, means supporting the chamber
-for vibratory movement, and means for vibrating the chamber to
agitate the lumps and cause them to abrade ad]acent lumps to
remove discrete particles of sand therefrom. The discrete partic-
les of sand accumulate on the floor and increase in volume as
vibration continues until the volume is sufficient to reach the
level of the exit, a screen carried by the chamber forms means
exteriorly thereof and is positioned to receive sand and other
material discharged from the exit, and a conveyor below the
screen is carried by the chamber forming means. The screen
permits discrete particles of sand to pass therethrough onto the j~
conveyor while prohibiting the passage of larger particles, and
a means directs the larger particles to one area and delivers
the sand particles to another area.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a side elevational view showing a vibratory
sand reclaiming apparatus in accordance with the present
invention;
6)4S779
Fig. 2 is an enlarged end view taken from the
position indicated by 2-2 of Fig. l; and
Fig. 3 is a vertical sectional view taken along
line 3-3 of Fig. 2.
DETAILED DESCR~PTION OF THE PREFERRED E~BODIMENT
Referring now to the drawings, there is shown a
closed housing 10 having a chamber 11 therein. In the bottom
of the chamber there is a floor 12 having a first portion 13
slanting downwardly from an entrance into the chamber. The
entrance can be closed by means of a door 14 hingedly secured
to the housing 10. The floor is provided with a second portion
15A slanting upwardly from the first portion and third and
fourth portions 15B and 15C slanting upwardly with increased
steepness from the portion 15A. Adjacent the upper end of
the floor portion 15C is an exit or discharge opening 16 in
the form of an elongated slot in the walls of the housing 10.
Secured to the underside of the housing 10 is a pair
of electric motors 17 and 18 provided with sha~ts 19 and 20,
respectively, with each shaft carrying a pair of eccentric
weights at each end, the weights at one end being shown at
21 and 22.
The housing also carries a third electric motor 24
positioned near the upper portion of the housing with the
motor having a shaft 25 carrying eccentric weights at each
end, one of which is shown at 26.
The housing 10 is mounted for vibratory movement
by means of brackets 27 secured thereto, which are supported
on isolation springs 28, in turn carried by base members 29.
79
A shelf 30 is secured to the housing 10 subjacent
the exit slot 16, the shelf slanting downwardly and opening
onto a screen 31 located in a small chamber 32 secured to the
right-hand portion of the housing 10. Below the screen 31
and within the chamber 32 is a floor 33. At the end of the
screen 31 is a wall 34 which serves to direct material unable
to pass through the screen 31 to a side opening 35. The
chamber 32 is open at the end of the floor 33 to permit
particles falling thereon to pass directly out of the chamber.
A flexible pipe 36 is secured to a source of suction for the
purposes hereinafter stated.
In operation, the sand lumps and any included material
coming from a mold into which a casting has been poured, are
introduced into the chamber 11 through the entrance 37 and the
gate 14 is thereupon closed. Electric motors 17 and 18 are
then started to impart a vibratory movement to the housing and
the lumps in the chamber 11 are rubbed against one another to
remove sand in the form of discrete particles therefrom. The
sand so removed builds up as a body of sand in the bottom of
the chamber and its accumulation, together with the vibratory
movement which has a conveying action to the right as seen in
Fig. 3, will move the discrete sand particles up to the dis-
charge exit 16. Inasmuch as the operation of the electric ;
motors 17 and 18 causes the housing to vibrate along the ~ine
indicated by the arrow A, material discharged through the exit
16 will be moved down the shelf 30 and onto the screen 31 and
will continue to be conveyed toward the right-hand end of the
screen. Discrete sand particles will fall through the screen
onto the floor 33 which is also vibrated in a conveying action
to cause the sand dropping thereon to be moved out of the housing
4~
~ ~45~79
into a suitable receptacle. Lumps of sand and other included
material too large to pass through the screen 31 will be moved
to the right-hand end of the chamber 32 into contact with the
wall 3~. Thus, such materials have a tendency to build up
against the wall 34, resulting in further abrading action of
the sand lumps unable to pass through the screen so that, in
effect, the chamber 32 acts as a secondary recovery chamber to
recover additional sand. Particles which will not further
abrade, and included metal rods, etc., will be directed by the
wall 34 out of the discharge exit 35 to be deposited in a
second receptacle.
Dust, for example from the resin binder or clay, is
removed from the chamber by means of the suction pipe 36.
After some period of use there will be an accumulation
of material in the bottom of the chamber 12, for example metal
rods, cores, and large irreducible lumps of sand. To remove
this material from the chamber, either the motor 17 or the motor
18 is stopped and motor 24 is started. The operation of these ;
two motors will cause the housing to vibrate along the direction
shown by the arrow B and thus the material on the floor 12 will
be conveyed to the left and out of the opening 37.
The apparatus shown and described is a modification and
readaptation of the apparatus shown in my United States patent
~,793,780 which, as shown in that patent, is primarily designed
to receive the castings themselves and remove the sand therefrom.
The apparatus thus shown has been modified as hereinabove des-
cribed in order to provide a sand recovery system capable of re-
claiming a very substantial portion of sand used in casting pro
cesses.
